Furnace



Patented Aug. 12, 1930 ATES PATENTy OFFME ROBERT A. ILG, OF CHICAGO,ILLINOIS ,FURNACE Vrlhis invention relates to furnaces, and the presentapplication constitutes a Vdivision of an application heretofore hled byme on the 28th day of October, 1926, Serial No. 144,673,

Patent No. 1,674,828.

.The furnace of thepresent invention `employs a furnace grate of themovable endless chain type, which facilitates filling the front end ofthe fire chamber with coal by permitting .the fire .door :to be locatedat a relatively low point and also facilitates the discharge of theashesat the rear end of the grate by automatically dumping .the `saine into areceptacle removable and replaceable through a door in the rear wall `of.the furnace; and .one object ofthe present invention' isto provideimproved means for .actuating the endless chain grate from a pointoutside the furnace. vAnother object is to provide improved grate acetuating means which will permit the grate and its support tobe withdrawnthrough the rear of the furnace and subsequently replaced in workingposition without requiring any preliminary disconnecting of the grateactuaiting mechanism.

Other objects and attendant advantages of the invention will be apparentto persons skilled in the art as the same-becomes better understood byreferenceto the yfollowing de tailed description, taken infconnectionwith the accompanying drawings wherein I have illustrated a practicaland ecient .embodiment of the principle of the invention, and in which-'and partly in vertical section, of my improved furnace; A

2 is a front elevation of the same;

3 is a rear elevation thereof;

Fig. 4 isa vertical longitudinal section taken on the staggered line 4-4of Fig. A2 parts at the front of they furnace being omitted;

Fig. 5 is a vertical transverse section taken von the line 5--5 of Fig;1;

Fig. 6 is a. vertical longitudinal section taken on the staggered yline6-6 of Fig. 2 parts at the front of the furnace being Iomitted. Y

Referring to the drawings, 10 designates Fig. 1 is a view, partly inside elevation Divided and this application filed March as an entirety arectangular sheet-metal housing or casing constituting the outer shellof the furnace structure and equipped with a front wall, the upperportion 11 of which may be of sheet steel or cast iron, while the lowerportion 12 is preferably constructed of cast iron to support the lireand draft doors, the operating mechanism of the grate, and the coolingchamber.

Located centrally within and extending lengthwise of the lower portionofthe shell or casing 10 is the combustion chamber yor lire box 13 ofthe furnace. This is a relatively narrow long structure, preferablyformed with a rounded or dome-shaped top as shown in Fig. 5, with itsrear end registering with an opening in the rear wall of the housingnormally closed by a door 14 (Fig. 3). On the bottom wall of thecombustion chamber are track rails 15 accommodating the wheels of aremovable truck 16 on which is mounted a fuel grate 17 of the well-knownendless link chain type mounted and supported on front and rear sprocketwheels 19 and 2O respectively. The grate is inclined upwardly from itsforward to its rear end, the forward end being but a slight distanceabove the floor of the ash pit, while its rear endis suiiicientlyelevated to enable the ashes to be discharged into a removable ash can21 locatedjbeneath the yrear end of the grate just inside the rear door14. This provides ample air space below the grate, and at the same timepermits` the frontdoor 22 of the combustion chamber to be located atarelatively low point lin the front wall of the fur-nace, thusfacilitating firing. f

Attached to or cast integral with the 'lower portion l2 of the frontwall and surrounding the opening yguarded by vthe door 22 is a hollowcasting` 23 adapted to contain water; the lower limb of said castingpreferably eX tending inwardly as shown at 23 above the lower frontportion of the kgrat-e and serving as a baille to prevent the body ofcoal on the latter from clogging between the front wall and the frontend of the grate. Water may be supplied to this jacket through a pipe24; and, where said acket is used as a hot water heater, the jacket' maybe additionally prorided with an outflow pipe 9: which, with the pipeQ41-, may be connected into a suitable water tank. In the event that thewater in the jacket 23 is used 'for humidifying the air, the pipe 25 maylead into one of the heated air passages the furnace at any convenientpoint. rl`his water jacket also serves to maintain a relatively lowtempera ture of the front wall of the lire chamber, preventing waste ofheat through radiation from the latter. The grate is moved to carry thebody of burning coal rearwardly and upwardly from time to time as freshfiring is required by a simple foot-operated actuating mechanism hereinshown as comprisinj;l gear wheel Q5 f it on the shaft of the lower gratesprocket `wheel i9, a pinion 2"? meshinej with said gear wheel L``ndfast on a shaft 28 journaled in the side walls of a suitable casing` 29mounted on the front wall, a ratchet wheel 8O fast on sbl it 28, andpedal lever 31 carrying a pawi 82 engaged with the ratchet wheel 30. The-",edal lever 3l is depressed by the foot to actuate the f ato, and. isreturned to neri al d position by a elevate` )ull s )rino At the l ttomof the front l e in which is mount- OO wall is a cleanout door ed theusual dra The furnace is so con" Ypairof symmeti" relativ y loneTpassages for the flow of the hot products of combustion to the sinelflue at the top of the furnace, together with a damper-controlledby-pass which may be employed to shorten the outflow passage when tiringup, or when a rapid increase in heat is desired; and also 'with asymmetrical pair of rela` tively lone; flow passe for the air to beheated said air passages being so arr-a1 ged. that the walls of the anosmoke pac,.. ges will be efficiently bathed by the air and the heatabstracted therefrom and transmitted to the air.

YWithin the outer sl ell or housing 10 and encldsingr the major portionof the top and sides of the lire bon 13 is a gelerally rectangular innersheet-metal as to provide hood-like structure eon'iprisine a top wall 3Gspaced from the top wall of the housing` l0, .side walls 37 parallelwith and spaced from the side walls of the housing and terminatinglslightly above the bottom wall of the latter, and a rear wall 3S. Asbest shown in Fir fl, .5 and G, the upper portion of this hood is subldivided by suitable partitions to provide draft flues for the productsof combustion and alsov a central rtical flue for the out- ,39designatos each of a pair of longitudinal partitions, and l0 and ill G)pair of transverse partitions between 'the longitudinal partitions Thesepartitions, with a portion ofthe rear wall 38 and the upper portion l1of the front wall of the outer casing together form a central outflowpassage or flue vdiating tins 60.

for the heated air communieating` with a flue section l2 in the top wallof the casing, to which latter is connected the warm air pipe or pipesleading to the registers. fs/here artificial circulation of the air isemployed, an opening is provided in the upper portion of the rear wallof the cater casing, in which is mounted a frame i3 supporting anelectric motor lll operating a direct driven fan 45, which forces thereturn air into the space between the outer and inner casings. Thisairfloods tbe space between the top w; ls Y the casings, flows Y thencedownwardly through the spaces between the side walls, thence upwardlybetween the side walls of the inner casing and the side walls of tilefire box, and thence upwardly through the warm air flue formed by thepar 'tions 39, l0 and lll, the rear vwall 38 of the inner casing and thefront wall ll of the outer casina` Between the longitudinal partitions39 and extending from the lower edge of the transverse partition s() tothe rear wall 38 is a horizontal plate L6 (F ig. and similarlypositioned between the longitudinal partitions 39 and extending from theupper edge of the transverse partition Lll to the rear wall S8 is ahorizontal plate 1l?. These plates are apertured, and fitted betweenthem is a shortby-pass flue section a9, rlhe upper and lower rectangularchambers thus formed communicate through upper and lower ports and 51respectively with longitudinally extending side flues formed between thelongitudinal partitions and the side walls 3T `of the hood. The bottomsof these side flues are closed by horizontal plates 52; and the rearbottom and top portions of the space between said side flues are closedby a horizontal plate 53 and the central longitudinal portion of the topwall 36, the former of which is apertured to receive the upper end of ashort flue section 55 mounted on and communicating with the combustionchamber 13, while the latter is apertured to receive a smoke dischargeflue 56. Attached to the rear wall of each of the side fines between theupper and lower ports 50 and 5l isa longitudinally extending bailleplate 57 that is preferably forwardly and downwardly inclined, as shownin Fig. et; and within the flue section t9 is a pivoted damper 5Smounted on an operating rod 59 extending through the front wall of thefurnace. r)The outer surfaces of the sidewalls 37 of the hood arepreferably equipped with heat ra- On the front wall ofthe outercasingare cleanoat doors i3l normally closing the frontends of the side smokelines. There the fan l5 is employed. to create 'au artificialcirculation of the air, itv may be located, as shown in Fig. l, withinthe cold air return flue 62 which ordinarily commu# nicates with agrating in the floor of the room above the furnace. Fresh air may be lllpermitted to the extent desired by providing on the side of the flue 62an opening guarded by a pivoted wing valve or damper 63 which may beclosed or opened more or less by a rod 64 which may extend to the roomabove. Automatic regulation of the temperature may, manifestly, beeffected by actuating the valve G3 by a thermostat; said valve thusserving not only to admit fresh air when desired, but also, whenthermostatically controlled, as an automatic temperature regulator.

The operation and advantages of the described furnace will it isbelieved be clear from the foregoing description of its structuralfeatures. The inclined chain grate provides increased space at theforward portion of the fire box for firing and makes it easy to lill thefront portion ofthe grate with coal, since it permits the lire door tobe located much closer to the floor line. rlhe elevation of the rear enoof the grate provides ample space for the location therebeneath of anash receptacle for catching all of the spent material, reducing thefrequency with which the liner portions of the ashes falling beneath thegrate have to be removed. And the mounting of the grate on a truckbodily removable through a door opening in the rear wall of the furnacegreatly facilitates cleaning, repairs and renewals when required andautomatically brings the grateactuating gears 26 and 2'? into registerwhen the grate is fully entered.

The provision of the water jacket around the fire door and above thelower end of the grate is valuable as maintaining` an even temperaturein the front of the iire chamber and a lower temperature at the pointwhere the new fueL is supplied tirough the fire door. This feature alsoperforms the function of the usual hot water coil in supplying hot waterfor any purpose, while it may also, be used for humidifying the airpassing through the furnace. ln lieu of employing water in the jacketfor the purposes above-mentioned, the outlet pipe 25 may be left open,and the inlet pipe 2li may be connected to the rear part of the furnacewhere fresh air is introduced l j; the fan, creating a plenum condition.This will provide a natural cool air circulation which will function thesame as the water in keeping down the temperature at the front of thefire chamber.

VEhe cool air, whether forced in by the fan, or flowing in by gravity,flows over the top and sides of the-inner shell, below the lower edgesof the side walls of the latter, thence upwardly between said side wallsand the sides and top of the fire chamber, and thence upwardly throughthe relatively large central air liu-e. clNith the damper 58 closed,smoke and hot gases of combustion flow from the fire bon through theshort neck 55, thence A rthrough the lower portsl into the two sideflues below the baffles 57, flowing forwardly beneath .the latter,thence around their Afront ends, thence rearwardly through the npperportions ofthe side fines, thence through the upper ports 550 into *theIdischarge flue :56. rlhe-wafll-s 36 and '37 of 'the :inner shell thusbecome highly heated through direct contact with the hot gases, and,since 1these walls are bathed by the vair flowing through the furnace, avery efficient heat exchange is .ef fected.

rThe use of ythin sheet-metal in the greater portion of the furnacestructure lends itself to economy in production and superior :eiliciencyin heatexchange yand whereempl-oyed in connection 'with artificial aircirculation., as shown, increases the rapidity with whch the roomsserved :by the furnace can be brought to a desired temperature.

vlll'lhile l have shown yand described any present improvements Vinassociation with a furnace vof .the hot air-type `which includes a heatexchange feature above the fire box, it is .to be vunderstood that Athe,present im'- provements relate to the fire box and girate structure andare applicableto other types of furnaces, such as those used in .hot'water and steam heating plants. lVhile l 'have herein shown anddescribed one practical and eflicient embodiment of the principle of theinvention, it is manifest that minor details of structure andarrangement mayT be resorted to without departing from the principle ofthe invention or sacrificing any of the benefits or advantages thereof.Hence, l do not limit the invention to the exact construction shown anddescribed for purposes of illustration, but reserve all such variations,modications and mechanical equivalents as fall within the spirit andpurview of the claims. f

l claim l. In a furnace, the combination with a combustion chamberhaving an opening in its rear wall, of track rails on the bottom of saidchamber, a truck movable into and out of said chamber through saidopening, on said rails, an upwardly and rearwardly inclined endlesschain grate mounted on said truck, a door closing said opening, andgearing for actuating said grate mounted partly on the latter and partlyon the front wall of said combustion chamber and adapted to beautomatically coupled when said grate is fully entered into saidcombustion chamber.

2. In a furnace, the combination with a combustion chamber iaving anopening in its rear wall, of a frame in said chamber, front an d rearshafts ournaled in said frame, sprocket wheels on said shafts, anendless chain grate mounted on said sprocket wheels, a gea-r fast onsaid front shaft, a shaft journaled on the front wall of said combustionchamber, a pinion fast on said last-named shaft meshing with said gear,a ratchet on .ist

said last-named Shaft, a lever pivoted on said last-named shaft yandcarrying a pawl co-operating with said ratchet, and a spring foreffecting the idle movement of said lever.

3. In a furnace, the combination With a combustion chamber havingl anopening in its rear Wall, a truck movable into and out of said chamberthrough said opening, front and rear shafts journaled in said truck7sprocket Wheels on said shafts, an endless chain grate mounted on saidsprocket Wheels, a gear fast on said front shaft, a shaft onrnaled onthe front Wall of said combustion chamber, a pinion fast on saidlast-nained shafts, means for turning said pinion, and track rails onthe bottom of said combustion chamber for guiding said truck into thelatter and bringing said gear and pinion into mesh.

4. In a "furnace, the combination with a combustion chamber havin@ anopening in its rear Wall, of a truck movable into and out of saidchamber through said opening,

chain grate mounted on sa/id truck, a door closing Said opening, and aremovable ash receptacle located below the elevated rear end of saidgrate.

ROBERT A. ILG.

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